Anderson, Charles,Herrera, Miguel,Ilangakoon, Anoukchika,Koya, KM,Moazzam, M,Mustika, Putu L,Sutaria, Dipani N
Cetacean bycatch in Indian Ocean tuna gillnet fisheries Journal Article
In: Endangered Species Research, vol. 41, no. 292, pp. 39-53, 2020, ISSN: 1863-5407.
Abstract | Links | BibTeX | Tags: Bycatch, Estimates, Extrapolation, Gill net, gillnet, Indian Ocean, mortality, Observer programmes, Oman, Pakistan, Sri Lanka, Trends, tuna fishery
@article{,
title = {Cetacean bycatch in Indian Ocean tuna gillnet fisheries},
author = {Anderson, Charles,Herrera, Miguel,Ilangakoon, Anoukchika,Koya, KM,Moazzam, M,Mustika, Putu L,Sutaria, Dipani N},
url = {https://www.int-res.com/prepress/n01008.html},
doi = {https://doi.org/10.3354/esr01008},
issn = {1863-5407},
year = {2020},
date = {2020-01-01},
journal = {Endangered Species Research},
volume = {41},
number = {292},
pages = {39-53},
abstract = {Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combine published results from 10 bycatch sampling programmes (1981–2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100,000 individuals yr–1 during 2004–2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, nor of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean. },
keywords = {Bycatch, Estimates, Extrapolation, Gill net, gillnet, Indian Ocean, mortality, Observer programmes, Oman, Pakistan, Sri Lanka, Trends, tuna fishery},
pubstate = {published},
tppubtype = {article}
}
Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combine published results from 10 bycatch sampling programmes (1981–2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100,000 individuals yr–1 during 2004–2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, nor of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean.
Al-Hashmi, Khalid A,Smith, Sharon L,Claereboudt, Michel,Piontkovski, Sergey A,Al-Azri, Adnan
Dynamics of potentially harmful phytoplankton in a semi-enclosed bay in the Sea of Oman Journal Article
In: Bulletin of Marine Science, vol. 91, no. 276, pp. 141-166, 2015, ISBN: 0007-4977.
Abstract | BibTeX | Tags: Harmful Algal Bloom, mortality, Oman, Sea of Oman
@article{,
title = {Dynamics of potentially harmful phytoplankton in a semi-enclosed bay in the Sea of Oman},
author = {Al-Hashmi, Khalid A,Smith, Sharon L,Claereboudt, Michel,Piontkovski, Sergey A,Al-Azri, Adnan},
issn = {0007-4977},
year = {2015},
date = {2015-01-01},
journal = {Bulletin of Marine Science},
volume = {91},
number = {276},
pages = {141-166},
abstract = {The dynamics of potentially harmful
phytoplankton in relation to environmental parameters was
investigated in the semi-enclosed Bay of Bandar Khayran (Sea
of Oman) from April 2006 through April 2011. In total, 24
potentially harmful algal species were identified, including
11 species of dinoflagellates and eight species of diatoms. The
dinoflagellates Prorocentrum minimum (Pavillard) Schiller,
1933, Scrippsiella trochoidea Balech ex Loeblich III, 1965,
and Noctiluca scintillans (Macartney) Kofoid and Swezy,
1921 were most abundant during the Southwest Monsoon
(SWM, July–September) and Northeast Monsoon (NEM,
January–March) seasons, while other species occurred in
low abundance and with no clear seasonal patterns. A dense
bloom of Cochlodinium polykrikoides Margalef, 1961 that
affected the distribution and abundance of other harmful
algal species (HAB) was observed for the first time in the Sea of
Oman during 2008–2009. Prorocentrum minimum increased
in abundance during and after the decay of the Cochlodinium
bloom while S. trochoidea was suppressed during this bloom,
increasing thereafter once again. Noctiluca scintillans
disappeared in the late SWM and NEM of 2008 and SWM of
2009, when blooms typically occur annually. Prorocentrum
minimum and S. trochoidea persisted throughout the annual
cycle of all years, enhancing their capability to bloom in the
region under favorable conditions of high light intensities
and relatively warm waters of low turbulence.},
keywords = {Harmful Algal Bloom, mortality, Oman, Sea of Oman},
pubstate = {published},
tppubtype = {article}
}
The dynamics of potentially harmful
phytoplankton in relation to environmental parameters was
investigated in the semi-enclosed Bay of Bandar Khayran (Sea
of Oman) from April 2006 through April 2011. In total, 24
potentially harmful algal species were identified, including
11 species of dinoflagellates and eight species of diatoms. The
dinoflagellates Prorocentrum minimum (Pavillard) Schiller,
1933, Scrippsiella trochoidea Balech ex Loeblich III, 1965,
and Noctiluca scintillans (Macartney) Kofoid and Swezy,
1921 were most abundant during the Southwest Monsoon
(SWM, July–September) and Northeast Monsoon (NEM,
January–March) seasons, while other species occurred in
low abundance and with no clear seasonal patterns. A dense
bloom of Cochlodinium polykrikoides Margalef, 1961 that
affected the distribution and abundance of other harmful
algal species (HAB) was observed for the first time in the Sea of
Oman during 2008–2009. Prorocentrum minimum increased
in abundance during and after the decay of the Cochlodinium
bloom while S. trochoidea was suppressed during this bloom,
increasing thereafter once again. Noctiluca scintillans
disappeared in the late SWM and NEM of 2008 and SWM of
2009, when blooms typically occur annually. Prorocentrum
minimum and S. trochoidea persisted throughout the annual
cycle of all years, enhancing their capability to bloom in the
region under favorable conditions of high light intensities
and relatively warm waters of low turbulence.
phytoplankton in relation to environmental parameters was
investigated in the semi-enclosed Bay of Bandar Khayran (Sea
of Oman) from April 2006 through April 2011. In total, 24
potentially harmful algal species were identified, including
11 species of dinoflagellates and eight species of diatoms. The
dinoflagellates Prorocentrum minimum (Pavillard) Schiller,
1933, Scrippsiella trochoidea Balech ex Loeblich III, 1965,
and Noctiluca scintillans (Macartney) Kofoid and Swezy,
1921 were most abundant during the Southwest Monsoon
(SWM, July–September) and Northeast Monsoon (NEM,
January–March) seasons, while other species occurred in
low abundance and with no clear seasonal patterns. A dense
bloom of Cochlodinium polykrikoides Margalef, 1961 that
affected the distribution and abundance of other harmful
algal species (HAB) was observed for the first time in the Sea of
Oman during 2008–2009. Prorocentrum minimum increased
in abundance during and after the decay of the Cochlodinium
bloom while S. trochoidea was suppressed during this bloom,
increasing thereafter once again. Noctiluca scintillans
disappeared in the late SWM and NEM of 2008 and SWM of
2009, when blooms typically occur annually. Prorocentrum
minimum and S. trochoidea persisted throughout the annual
cycle of all years, enhancing their capability to bloom in the
region under favorable conditions of high light intensities
and relatively warm waters of low turbulence.
Braulik,G.,Ranjbar,S.,Owfi,F.,Aminrad,T.,Dakhteh,S.M.H.,Kamrani,E.,Mohsenizadeh,F.
Marine Mammal Records from Iran Journal Article
In: Journal of Cetacean Research and Management, vol. 11, no. 334, pp. 49-63, 2010.
Abstract | BibTeX | Tags: abundance, bottlenose dolphin, Bryde's whale, Common dolphin, conservation, Distribution, dolphin, dugong, fin whale, Finless Porpoise, fishing gear, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, killer whale, location, mammals, management, marine, marine mammal, Marine mammals, mortality, mysticete, mysticetes, Oman, Porpoise, Risso's dolphin, rough-toothed dolphin, Spinner dolphin, whale, whales
@article{,
title = {Marine Mammal Records from Iran},
author = {Braulik,G.,Ranjbar,S.,Owfi,F.,Aminrad,T.,Dakhteh,S.M.H.,Kamrani,E.,Mohsenizadeh,F.},
year = {2010},
date = {2010-01-01},
journal = {Journal of Cetacean Research and Management},
volume = {11},
number = {334},
pages = {49-63},
abstract = {A total of 114 marine mammal records of 14 species were compiled from Iranian coastalwaters of the Persian Gulf and Gulf of Oman. Eighty-one were from the Persian Gulf, 23from the Gulf of Oman and 10 were of unknown location. Records of finless porpoise(Neophocaena phocaenoides) (24), Indo-pacific humpback dolphin (Sousa chinensis) (22)and Indo-pacific bottlenose dolphin (Tursiops aduncus) (21) were by far the most numerousa probable reflection of their inshore distribution and local abundance. Other speciesrecorded were common dolphin (Delphinus capensis tropicalis), rough-toothed dolphin(Steno bredanensis), striped dolphin (Stenella coeruleoalba), spinner dolphin (Stenellalongirostris), Risso's dolphin (Grampus griseus), false killer whale (Pseudorca crassidens),sperm whale (Physeter macrocephalus) and dugong (Dugong dugon). Records of 24Mysticetes were compiled, 11 of which were tentatively identified as Bryde's whales(Balaenoptera edeni), three as Fin whales (Balaenoptera physalus), three as Humpbackwhales (Megaptera novaeangliae) and the remainder were unidentified. The largest threat tomarine mammals in Iran is likely to be incidental capture in fishing gear. Nine finlessporpoises were recorded as bycatch and this and other coastal species may be declining dueto unsustainable mortality rates. Other threats to the marine environment are discussed andrecommended marine mammal conservation and management small projects are described.},
keywords = {abundance, bottlenose dolphin, Bryde's whale, Common dolphin, conservation, Distribution, dolphin, dugong, fin whale, Finless Porpoise, fishing gear, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, killer whale, location, mammals, management, marine, marine mammal, Marine mammals, mortality, mysticete, mysticetes, Oman, Porpoise, Risso's dolphin, rough-toothed dolphin, Spinner dolphin, whale, whales},
pubstate = {published},
tppubtype = {article}
}
A total of 114 marine mammal records of 14 species were compiled from Iranian coastalwaters of the Persian Gulf and Gulf of Oman. Eighty-one were from the Persian Gulf, 23from the Gulf of Oman and 10 were of unknown location. Records of finless porpoise(Neophocaena phocaenoides) (24), Indo-pacific humpback dolphin (Sousa chinensis) (22)and Indo-pacific bottlenose dolphin (Tursiops aduncus) (21) were by far the most numerousa probable reflection of their inshore distribution and local abundance. Other speciesrecorded were common dolphin (Delphinus capensis tropicalis), rough-toothed dolphin(Steno bredanensis), striped dolphin (Stenella coeruleoalba), spinner dolphin (Stenellalongirostris), Risso's dolphin (Grampus griseus), false killer whale (Pseudorca crassidens),sperm whale (Physeter macrocephalus) and dugong (Dugong dugon). Records of 24Mysticetes were compiled, 11 of which were tentatively identified as Bryde's whales(Balaenoptera edeni), three as Fin whales (Balaenoptera physalus), three as Humpbackwhales (Megaptera novaeangliae) and the remainder were unidentified. The largest threat tomarine mammals in Iran is likely to be incidental capture in fishing gear. Nine finlessporpoises were recorded as bycatch and this and other coastal species may be declining dueto unsustainable mortality rates. Other threats to the marine environment are discussed andrecommended marine mammal conservation and management small projects are described.
Baldwin,R.M.
Oman's humpback whales (Megaptera novaeangliae) Journal Article
In: The Journal of Oman Studies, vol. 11 , no. 316, pp. 11-18, 2000.
Abstract | BibTeX | Tags: abundance, Arabian Sea, behaviour, conservation, Distribution, ecology, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, megaptera novaeangliae, mortality, occurrence, Oman, population, population identity, status, survey, whale, whales
@article{,
title = {Oman's humpback whales (Megaptera novaeangliae) },
author = {Baldwin,R.M.},
year = {2000},
date = {2000-01-01},
journal = {The Journal of Oman Studies},
volume = {11 },
number = {316},
pages = {11-18},
abstract = {Data are presented on the general distribution and abundance of humpback whales off the coast of the Sultanate of Oman, with particular reference to observations made during an offshore seismic survey in the Arabian Sea in November 1997. Additional information is presented on seasonal occurrence, ecology and behaviour, external appearance, conservation, mortality, incidental capture, population status and identity of Oman's humpback whales. The data generally support the notion of year-round residency of humpback whales off the coast of Oman, but indicate the need for further research to establish whether the low frequency of positive records during summer months is a true reflection of seasonal distribution. Other research on humpback whales in the region is recommended.},
keywords = {abundance, Arabian Sea, behaviour, conservation, Distribution, ecology, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, megaptera novaeangliae, mortality, occurrence, Oman, population, population identity, status, survey, whale, whales},
pubstate = {published},
tppubtype = {article}
}
Data are presented on the general distribution and abundance of humpback whales off the coast of the Sultanate of Oman, with particular reference to observations made during an offshore seismic survey in the Arabian Sea in November 1997. Additional information is presented on seasonal occurrence, ecology and behaviour, external appearance, conservation, mortality, incidental capture, population status and identity of Oman's humpback whales. The data generally support the notion of year-round residency of humpback whales off the coast of Oman, but indicate the need for further research to establish whether the low frequency of positive records during summer months is a true reflection of seasonal distribution. Other research on humpback whales in the region is recommended.
Roman,M.,Smith,S.,Wishner,K.,Gowing,M.,Zhang,X.S.
Mezozooplankton production and grazing the Arabian Sea Journal Article
In: Deep-Sea Research Part II, vol. 47, no. 452, pp. 1423-1450, 2000.
Abstract | BibTeX | Tags: abundance, Arabian Sea, ecology, marine, mortality, multivariate, temperature, zooplankton
@article{,
title = {Mezozooplankton production and grazing the Arabian Sea},
author = {Roman,M.,Smith,S.,Wishner,K.,Gowing,M.,Zhang,X.S.},
year = {2000},
date = {2000-01-01},
journal = {Deep-Sea Research Part II},
volume = {47},
number = {452},
pages = {1423-1450},
abstract = {Growth rates, grazing and fecal pellet production by mesozooplankton size classes in the surface 200 m are compared over two inshore/offshore transects in the Northern Arabian Sea during different monsoon seasons. We derived these rate parameters from measured biomass and several empirical models that estimate copepod production from temperature, body weight and food availability. The multivariate regression published by Hirst and Sheader (1997, Marine Ecology Progress Series, 154, 155-165) gave the most reasonable rate estimates when compared to direct grazing measurements as well as published data on copepod ingestion and growth rates. In general, zooplankton rate estimates were highest at the inshore stations where phytoplankton production and zooplankton biomass were maximum. Overall cruise means of zooplankton biomass and rate estimates during the early and late NE Monsoon, Spring Inter-monsoon and SW Monsoon were not significantly different. The estimated zooplankton community (all size fractions) growth rate averaged 0.12d(-I) over all stations during the different monsoon seasons. Although smaller zooplankton size fractions grew faster, slower growing > 2 mm zooplankton dominated the zooplankton biomass of the Arabian Sea and this resulted in a lower overall community growth rate. Estimated total carbon (phytoplankton, protozoa and detritus) ingestion averaged 44 mM C m(-2) d(-I), which was approximately 40% of primary production, Expressed as a percentage ofbiomass, we found that zooplankton ingested approximately 400/0 of their body carbon d( -1 ). Zooplankton fecal pellet production averaged 13 mM C m(-2) d(-I) or roughly 12% of primary production. This estimated fecal pellet production was greater than measurements of the export flux during the NE Monsoon and Spring Intermonsoon. However, estimated fecal pellet production was less than measured export flux during the SW Monsoon when sinking phytoplankton likely contributed directly to the export flux. Our data suggest that relative to other ocean basins, the grazing impact of mesozooplankton is significant in the Arabian Sea as a consequence of the high zooplankton biomass, abundance of diatoms, and warm temperatures, which result in high zooplankton metabolic demands and growth rates. The observation that the average zooplankton biomass ( 110 mM C m( -2¯) did not change significantly over the monsoon seasons suggests that zooplankton production (13 mM C m(-2) d(-I)) and zooplankton mortality were similar over the study interval. (C) 2000 Elsevier Science Ltd. All rights reserved.},
keywords = {abundance, Arabian Sea, ecology, marine, mortality, multivariate, temperature, zooplankton},
pubstate = {published},
tppubtype = {article}
}
Growth rates, grazing and fecal pellet production by mesozooplankton size classes in the surface 200 m are compared over two inshore/offshore transects in the Northern Arabian Sea during different monsoon seasons. We derived these rate parameters from measured biomass and several empirical models that estimate copepod production from temperature, body weight and food availability. The multivariate regression published by Hirst and Sheader (1997, Marine Ecology Progress Series, 154, 155-165) gave the most reasonable rate estimates when compared to direct grazing measurements as well as published data on copepod ingestion and growth rates. In general, zooplankton rate estimates were highest at the inshore stations where phytoplankton production and zooplankton biomass were maximum. Overall cruise means of zooplankton biomass and rate estimates during the early and late NE Monsoon, Spring Inter-monsoon and SW Monsoon were not significantly different. The estimated zooplankton community (all size fractions) growth rate averaged 0.12d(-I) over all stations during the different monsoon seasons. Although smaller zooplankton size fractions grew faster, slower growing > 2 mm zooplankton dominated the zooplankton biomass of the Arabian Sea and this resulted in a lower overall community growth rate. Estimated total carbon (phytoplankton, protozoa and detritus) ingestion averaged 44 mM C m(-2) d(-I), which was approximately 40% of primary production, Expressed as a percentage ofbiomass, we found that zooplankton ingested approximately 400/0 of their body carbon d( -1 ). Zooplankton fecal pellet production averaged 13 mM C m(-2) d(-I) or roughly 12% of primary production. This estimated fecal pellet production was greater than measurements of the export flux during the NE Monsoon and Spring Intermonsoon. However, estimated fecal pellet production was less than measured export flux during the SW Monsoon when sinking phytoplankton likely contributed directly to the export flux. Our data suggest that relative to other ocean basins, the grazing impact of mesozooplankton is significant in the Arabian Sea as a consequence of the high zooplankton biomass, abundance of diatoms, and warm temperatures, which result in high zooplankton metabolic demands and growth rates. The observation that the average zooplankton biomass ( 110 mM C m( -2¯) did not change significantly over the monsoon seasons suggests that zooplankton production (13 mM C m(-2) d(-I)) and zooplankton mortality were similar over the study interval. (C) 2000 Elsevier Science Ltd. All rights reserved.
Wilson,S.C.,Klaus,R.
The Gulf of Aden Book
Pergamon, Elsevier Science, 2000.
Abstract | BibTeX | Tags: Arabian Sea, conservation, coral, dolphin, dolphins, East Africa, enforcement, Fisheries, Gulf of Aden, Indian Ocean, management, marine, mortality, oceanography, Oman, pollution, productivity, Red Sea, turtles
@book{,
title = {The Gulf of Aden},
author = {Wilson,S.C.,Klaus,R.},
year = {2000},
date = {2000-01-01},
journal = {Seas at the Millennium: an Environmental Evaluation: Volume II Regional Chapters: The Indian Ocean to the Pacific},
number = {510},
pages = {47-61},
publisher = {Pergamon, Elsevier Science},
abstract = {The Gulf of Aden lies between southern Arabia and the Horn of Africa and connects with the Red Sea and Indian Ocean. The Socotra Archipelago lies at its entrance, off the Horn of Africa. The largest influence comes from the reversing monsoon system with strong and persistent winds that blow from the southwest in summer, and from the northeast in winter. These also cause a reversal in the direction of surface currents. Associated with the summer monsoon are upwelling areas along the eastern coast of Yemen, and one centred on the Somali coast southwest of Socotra. Both have a profound effect on coastal habitats and stimulate high marine productivity which supports a rich fishery. Marine biodiversity is relatively high since the area is a transition zone between the Red Sea, Southern Arabia and East Africa. Terrestrial diversity, particularly in the flora of Socotra, is also elevated by high levels of endemism. Coasts are mainly exposed sandy beaches separated by rocky headlands. Coral communities and reefs have developed most notably in Djibouti and offshore islands of Somalia. Seagrasses are relatively uncommon, and mangrove stands are most abundant to the west and southwest. A striking feature of rocky shores is the abundant macroalgae that appears following the onset of the Southwest Monsoon in particular. Green turtles nest in tens of thousands, and thousands of dolphins have also recently been observed. Perhaps the most serious single threat to sustainable use of marine resources comes from overfishing, particularly by industrial fleets that operate with or without licenses. Some stocks have collapsed or are showing signs of strain, including cuttlefish, shark and lobster. Wildlife species are also harvested and incidental mortality appears high. Levels of pollution are low except around larger towns where sewage and solid wastes are starting to affect resources. Chronic oil pollution originating from tankers is also cause for concern, but levels appear to be low. Harsh environmental conditions and lack of infrastructure limits exploitation of coastal resources and traditional methods of limiting exploitation are still effective. Political instability and unrest, and lack of funding have hampered coastal management, though a strategic action plan for the conservation and protection of the marine environment has recently been prepared by PERSGA as a crucial first step. There are only two small marine parks in the region, both in Djibouti.},
keywords = {Arabian Sea, conservation, coral, dolphin, dolphins, East Africa, enforcement, Fisheries, Gulf of Aden, Indian Ocean, management, marine, mortality, oceanography, Oman, pollution, productivity, Red Sea, turtles},
pubstate = {published},
tppubtype = {book}
}
The Gulf of Aden lies between southern Arabia and the Horn of Africa and connects with the Red Sea and Indian Ocean. The Socotra Archipelago lies at its entrance, off the Horn of Africa. The largest influence comes from the reversing monsoon system with strong and persistent winds that blow from the southwest in summer, and from the northeast in winter. These also cause a reversal in the direction of surface currents. Associated with the summer monsoon are upwelling areas along the eastern coast of Yemen, and one centred on the Somali coast southwest of Socotra. Both have a profound effect on coastal habitats and stimulate high marine productivity which supports a rich fishery. Marine biodiversity is relatively high since the area is a transition zone between the Red Sea, Southern Arabia and East Africa. Terrestrial diversity, particularly in the flora of Socotra, is also elevated by high levels of endemism. Coasts are mainly exposed sandy beaches separated by rocky headlands. Coral communities and reefs have developed most notably in Djibouti and offshore islands of Somalia. Seagrasses are relatively uncommon, and mangrove stands are most abundant to the west and southwest. A striking feature of rocky shores is the abundant macroalgae that appears following the onset of the Southwest Monsoon in particular. Green turtles nest in tens of thousands, and thousands of dolphins have also recently been observed. Perhaps the most serious single threat to sustainable use of marine resources comes from overfishing, particularly by industrial fleets that operate with or without licenses. Some stocks have collapsed or are showing signs of strain, including cuttlefish, shark and lobster. Wildlife species are also harvested and incidental mortality appears high. Levels of pollution are low except around larger towns where sewage and solid wastes are starting to affect resources. Chronic oil pollution originating from tankers is also cause for concern, but levels appear to be low. Harsh environmental conditions and lack of infrastructure limits exploitation of coastal resources and traditional methods of limiting exploitation are still effective. Political instability and unrest, and lack of funding have hampered coastal management, though a strategic action plan for the conservation and protection of the marine environment has recently been prepared by PERSGA as a crucial first step. There are only two small marine parks in the region, both in Djibouti.
Caron,D.A.,Dennett,M.R.
Phytoplankton growth and mortality during the 1995 Northeast Monsoon and Spring Intermonsoon in the Arabian Sea Journal Article
In: Deep-Sea Research Part II, vol. 46, no. 63, pp. 1665-1690, 1999.
Abstract | BibTeX | Tags: Arabian Sea, chlorophyll, growth, mortality, Oceanic, trend, Trends
@article{,
title = {Phytoplankton growth and mortality during the 1995 Northeast Monsoon and Spring Intermonsoon in the Arabian Sea},
author = {Caron,D.A.,Dennett,M.R.},
year = {1999},
date = {1999-01-01},
journal = {Deep-Sea Research Part II},
volume = {46},
number = {63},
pages = {1665-1690},
abstract = {Phytoplankton growth rates and mortality rates were experimentally examined at eight stations in the Arabian Sea along the U.S. JGOFS cruise track during the 1995 Northeast Monsoon (January) and Spring Intermonsoon (March-April). Instantaneous growth rates averaged over an entire cruise were approximately twice as high during the NE Monsoon than during the Spring Intermonsoon period (overall averages of 0.84 ñ 0.29 (s.d.) versus 0.44 ñ 0.19 d-1). Average herbivore grazing (mortality) rates, however, were quite similar for the two seasons (overall averages of 0.35 ñ 0.18 and 0.30 ñ 0.17 d-1 for the NE Monsoon and Spring Intermonsoon, respectively). The absolute amounts of phytoplankton biomass consumed during each season also were similar (29 and 25% of standing stock consumed d-1 for the January and March-April cruises, respectively), as were the geographical trends of this removal. These seasonal trends in growth and removal rates resulted in net phytoplankton growth rates that were considerably higher during the January cruise (0.48 d-1) than during the March-April cruise (0.14 d-1). That is, phytoplankton production was more closely balanced during the Spring Intermonsoon season (87% of daily primary production consumed) relative to the NE Monsoon season (49% of daily primary production consumed). Station-to-station variability was high for rate measurements during either cruise. Nevertheless, there was a clear onshore-offshore trend in the absolute rate of removal of phytoplankton biomass (æg chlorophyll consumed l-1 d-1) during both cruises. Coastal stations had removal rates that were typically 2-4 times higher than removal rates at oceanic stations.},
keywords = {Arabian Sea, chlorophyll, growth, mortality, Oceanic, trend, Trends},
pubstate = {published},
tppubtype = {article}
}
Phytoplankton growth rates and mortality rates were experimentally examined at eight stations in the Arabian Sea along the U.S. JGOFS cruise track during the 1995 Northeast Monsoon (January) and Spring Intermonsoon (March-April). Instantaneous growth rates averaged over an entire cruise were approximately twice as high during the NE Monsoon than during the Spring Intermonsoon period (overall averages of 0.84 ñ 0.29 (s.d.) versus 0.44 ñ 0.19 d-1). Average herbivore grazing (mortality) rates, however, were quite similar for the two seasons (overall averages of 0.35 ñ 0.18 and 0.30 ñ 0.17 d-1 for the NE Monsoon and Spring Intermonsoon, respectively). The absolute amounts of phytoplankton biomass consumed during each season also were similar (29 and 25% of standing stock consumed d-1 for the January and March-April cruises, respectively), as were the geographical trends of this removal. These seasonal trends in growth and removal rates resulted in net phytoplankton growth rates that were considerably higher during the January cruise (0.48 d-1) than during the March-April cruise (0.14 d-1). That is, phytoplankton production was more closely balanced during the Spring Intermonsoon season (87% of daily primary production consumed) relative to the NE Monsoon season (49% of daily primary production consumed). Station-to-station variability was high for rate measurements during either cruise. Nevertheless, there was a clear onshore-offshore trend in the absolute rate of removal of phytoplankton biomass (æg chlorophyll consumed l-1 d-1) during both cruises. Coastal stations had removal rates that were typically 2-4 times higher than removal rates at oceanic stations.
Phillip Clapham, Sharon Young, Robert L. Brownell Jr
Baleen whales: conservation issues and the status of the most endangered populations Journal Article
In: Mammal Review, vol. 29 , no. 69, pp. 35-60, 1999.
Abstract | Links | BibTeX | Tags: abundance, Arabian Sea, Arctic, Balaena mysticetus, baleen whale, baleen whales, Blue whale, bowhead whale, bowhead whales, conservation, contaminants, disease, endangered, Entanglement, Eubalaena glacialis, fishing gear, gray whales, habitat degradation, Humpback Whale, humpback whales, mortality, Okhotsk Sea, population, populations, right whale, right whales, ship-strike, southern right whales, status, stocks, whale, whales, whaling
@article{,
title = {Baleen whales: conservation issues and the status of the most endangered populations },
author = {Phillip Clapham, Sharon Young, Robert L. Brownell Jr},
doi = {https://doi.org/10.1046/j.1365-2907.1999.00035.x},
year = {1999},
date = {1999-01-01},
urldate = {1999-01-01},
journal = {Mammal Review},
volume = {29 },
number = {69},
pages = {35-60},
abstract = {Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions: populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right N hales Eubalaena glacialis. Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations. western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and. where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling. existing data indicate strong recovery in most studied populations of these species.},
keywords = {abundance, Arabian Sea, Arctic, Balaena mysticetus, baleen whale, baleen whales, Blue whale, bowhead whale, bowhead whales, conservation, contaminants, disease, endangered, Entanglement, Eubalaena glacialis, fishing gear, gray whales, habitat degradation, Humpback Whale, humpback whales, mortality, Okhotsk Sea, population, populations, right whale, right whales, ship-strike, southern right whales, status, stocks, whale, whales, whaling},
pubstate = {published},
tppubtype = {article}
}
Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions: populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right N hales Eubalaena glacialis. Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations. western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and. where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling. existing data indicate strong recovery in most studied populations of these species.
Baldwin,R.
Humpback whales Technical Report
no. 19, 1998.
Abstract | BibTeX | Tags: abundance, Arabian Sea, behaviour, conservation, Distribution, ecology, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, megaptera novaeangliae, mortality, occurrence, Oman, population, population identity, status, survey, whale, whales
@techreport{,
title = {Humpback whales },
author = {Baldwin,R.},
year = {1998},
date = {1998-01-01},
volume = {SC/50/CAWS21},
number = {19},
pages = {1-6},
abstract = {Data are presented on the general distribution and abundance of humpback whales off the coast of the Sultanate of Oman, with particular reference to observations made during an offshore seismic survey in the Arabian Sea in November 1997. Additional information is presented on seasonal occurrence, ecology and behaviour, external appearance, conservation, mortality, incidental capture and population status and identity of Oman's humpback whales. The data generally support the notion of year-round residency of humpback whales off the coast of Oman, but indicate the need for further research to establish whether the low frequency of positive records during summer months is a true reflection of seasonal distribution. Other research on humpback whales in the region is recommended.},
keywords = {abundance, Arabian Sea, behaviour, conservation, Distribution, ecology, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, megaptera novaeangliae, mortality, occurrence, Oman, population, population identity, status, survey, whale, whales},
pubstate = {published},
tppubtype = {techreport}
}
Data are presented on the general distribution and abundance of humpback whales off the coast of the Sultanate of Oman, with particular reference to observations made during an offshore seismic survey in the Arabian Sea in November 1997. Additional information is presented on seasonal occurrence, ecology and behaviour, external appearance, conservation, mortality, incidental capture and population status and identity of Oman's humpback whales. The data generally support the notion of year-round residency of humpback whales off the coast of Oman, but indicate the need for further research to establish whether the low frequency of positive records during summer months is a true reflection of seasonal distribution. Other research on humpback whales in the region is recommended.
Baldwin,R.M.
Humpback whales (Megaptera novaeangliae) of the Sultanate of Oman Technical Report
no. 315, 1998.
Abstract | BibTeX | Tags: abundance, Arabian Sea, behaviour, conservation, Distribution, ecology, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, megaptera novaeangliae, mortality, occurrence, Oman, population, population identity, status, survey, whale, whales
@techreport{,
title = {Humpback whales (Megaptera novaeangliae) of the Sultanate of Oman },
author = {Baldwin,R.M.},
year = {1998},
date = {1998-01-01},
journal = {Report presented to the Scientific Committee of the International Whaling Commission},
volume = {SC/50/CAWS21 },
number = {315},
pages = {1-6},
abstract = {Data are presented on the general distribution and abundance of humpback whales off the coast of the Sultanate of Oman, with particular reference to observations made during an offshore seismic survey in the Arabian Sea in November 1997. Additional information is presented on seasonal occurrence, ecology and behaviour, external appearance, conservation, mortality, incidental capture and population status and identity of Oman's humpback whales. The data generally support the notion of year-round residency of humpback whales off the coast of Oman, but indicate the need for further research to establish whether the low frequency of positive records during summer months is a true reflection of seasonal distribution. Other research on humpback whales in the region is recommended.},
keywords = {abundance, Arabian Sea, behaviour, conservation, Distribution, ecology, Gulf of Oman, Humpback Whale, humpback whales, incidental capture, megaptera novaeangliae, mortality, occurrence, Oman, population, population identity, status, survey, whale, whales},
pubstate = {published},
tppubtype = {techreport}
}
Data are presented on the general distribution and abundance of humpback whales off the coast of the Sultanate of Oman, with particular reference to observations made during an offshore seismic survey in the Arabian Sea in November 1997. Additional information is presented on seasonal occurrence, ecology and behaviour, external appearance, conservation, mortality, incidental capture and population status and identity of Oman's humpback whales. The data generally support the notion of year-round residency of humpback whales off the coast of Oman, but indicate the need for further research to establish whether the low frequency of positive records during summer months is a true reflection of seasonal distribution. Other research on humpback whales in the region is recommended.
Salm,R.V.
Impact of fisheries on the environment and wildlife: Sultanate of Oman Technical Report
no. 467, 1992.
Abstract | BibTeX | Tags: by-catch, cetaceans, coastal zone management, coral, Fisheries, mortality, Oman, turtles
@techreport{,
title = {Impact of fisheries on the environment and wildlife: Sultanate of Oman},
author = {Salm,R.V.},
year = {1992},
date = {1992-01-01},
journal = {Scientific Results of the IUCN Coastal Zone Management Project},
volume = {CZMP4:F17},
number = {467},
pages = {1-19},
abstract = {The report highlights fisheries related damage to coral communities, and fisheries related mortality of turtles and cetaceans in the Sultanate of Oman. It includes detailed tables of dead turtles and dead cetaceans showing evidence of direct harvest, found during the IUCN Coastal Zone Management Survey, conducted in Oman between 1987 and 1991.},
keywords = {by-catch, cetaceans, coastal zone management, coral, Fisheries, mortality, Oman, turtles},
pubstate = {published},
tppubtype = {techreport}
}
The report highlights fisheries related damage to coral communities, and fisheries related mortality of turtles and cetaceans in the Sultanate of Oman. It includes detailed tables of dead turtles and dead cetaceans showing evidence of direct harvest, found during the IUCN Coastal Zone Management Survey, conducted in Oman between 1987 and 1991.
Gallagher,M.D.
Collection of skulls of cetacea: Odondoceti from Bahrain, United Arab Emirates and Oman, 1969 - 1990 Book
UNEP, 1991.
Abstract | BibTeX | Tags: bottlenose dolphin, cetacea, cetacean, cetaceans, Common dolphin, Cuvier's beaked whale, dwarf sperm whale, false killer whale, fishing gear, hump-backed dolphin, incidental capture, Indian Ocean, marine, marine mammal, mass mortality, morphology/anatomy, mortality, Oman, Risso's dolphin, sanctuaries, skull, skulls, sperm whale, Spinner dolphin, spotted dolphin, Strandings, Striped dolphin, tropical dolphin, United Arab Emirates
@book{,
title = {Collection of skulls of cetacea: Odondoceti from Bahrain, United Arab Emirates and Oman, 1969 - 1990},
author = {Gallagher,M.D.},
year = {1991},
date = {1991-01-01},
journal = {Cetaceans and Cetacean Research in the Indian Ocean Sanctuary: Marine Mammal Technical Report Number 3},
number = {375},
pages = {89-97},
publisher = {UNEP},
abstract = {This paper details the collections of odontocete cetacean skulls from Bahrain, the United Arab Emirates and Oman, 1969-90. Causes of death of specimens are unknown but the likelihood of natural strandings, incidental capture in fishing gear and mass mortality are discussed.},
keywords = {bottlenose dolphin, cetacea, cetacean, cetaceans, Common dolphin, Cuvier's beaked whale, dwarf sperm whale, false killer whale, fishing gear, hump-backed dolphin, incidental capture, Indian Ocean, marine, marine mammal, mass mortality, morphology/anatomy, mortality, Oman, Risso's dolphin, sanctuaries, skull, skulls, sperm whale, Spinner dolphin, spotted dolphin, Strandings, Striped dolphin, tropical dolphin, United Arab Emirates},
pubstate = {published},
tppubtype = {book}
}
This paper details the collections of odontocete cetacean skulls from Bahrain, the United Arab Emirates and Oman, 1969-90. Causes of death of specimens are unknown but the likelihood of natural strandings, incidental capture in fishing gear and mass mortality are discussed.